Ultra-High Quantum Dot Color Conversion in Graphene-Connected Nanorod Micro-LEDs via Non-Radiative Energy Transfer and Localized Surface Plasmon Resonance

Journal article, 2025

In the field of quantum dot (QD)-based micro-light-emitting diode (mu LED) full-color display technology, achieving high color conversion efficiency (CCE) is one of the key performance indicators. In this work, a mu LED architecture is presented that incorporates an optimized nanorod array, with QDs and nanogapped gold nanoparticles (AuNNPs) embedded in the inter-rod gaps. By harnessing non-radiative energy transfer (NRET) and localized surface plasmon resonance (LSPR), the absorption and utilization of quantum well (QW) energy by the QDs are significantly enhanced. To ensure efficient current spreading and uniform light emission, graphene is employed as a transparent conductive layer to interconnect the nanorods. As graphene can transfer photogenerated carriers to the QDs, enhancing their quantum yield, it is also introduced as an intermediate insertion layer and support layer, allowing the integration of a second layer of QDs and AuNNPs on the light-emitting surface. This design maintains the electrical performance of the nanorod mu LED while achieving ultra-high CCE. Experimental results demonstrate that the proposed mu LED with nanorod structures and AuNNPs achieves a maximum CCE of 94%, representing a 102% improvement compared to conventional planar mu LEDs. These findings offer promising insights for advancing high-performance, full-color mu LED display technologies through nanoscale engineering.